Pistol ID and Value

Someone is selling this .56 cal pistol for around $350, though I could maybe get it for less if I ask. They claim it is Revolutionary War Era, and converted to percussion cap. It looks to me like the lock was replaced rather than converted, but I am not sure. What do you guys think about this pistol? How old is it, and how much is it probably worth.

Sorry for the bad photos, this was the best I could do while I was there.

 

I'd say it's worth about $25 as a curio. I'd guess Middle Eastern late 1800s.

 

1760 Stanton of London....

I'd be looking for something more in this vein.
Yours looks beat up...missing pieces...added pieces......
Leave it for the next buyer to come along.....& study up on the weapons from The American Revolutionary War, also known as the American War of Independence, period.

 

I have a very similar pistol, also percussion. Not sure if it was a conversion or not, but it had been extensively modified/repaired - barrel shortened, stock whittled away to match; cracks near barrel repaired with nails - and it was not great quality to start with. Bought in the Middle East, near Jerusalem around 1960 as a curio, very cheaply....$10 or so in 1960 dollars. I'd agree with the date of late 1800s, early 1900s. I've heard that such pistols were used for many years in the Middle east even after technology had moved on.
That's the Middle Eastern where mine was found, not sure where it was originally made, most marks having been worn or rusted away.